TypeScript

In TypeScript, we'll be using the fetch API to send HTTP requests. Here's how you can use the book search API with TypeScript:

First, define an interface for the book data:

interface Book {
    title: string;
    author: string;
}

Next, write the searchBook function using async/await:

async function searchBook(query: string): Promise<Book[]> {
    const url = 'https://api.promptjoy.com/api/mVMCpq';
    const options: RequestInit = {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
            'x-api-key': process.env.PROMPTJOY_API_KEY
        },
        body: JSON.stringify({ query })
    };

    const response = await fetch(url, options);

    if (!response.ok) {
        throw new Error(`HTTP error! status: ${response.status}`);
    }

    const data: Book[] = await response.json();
    return data;
}

You can call this function with the search term as follows:

searchBook('your_search_term')
    .then(data => console.log(data))
    .catch(error => console.log('There was an error!', error));

This example uses the Fetch API, which returns Promises. If you're not familiar with Promises or async/await syntax, you might want to read up on those.

Remember to handle exceptions and errors as needed in your actual application code.

Note: In this example, the API key is retrieved from environment variables for security reasons. Ensure that you've set the PROMPTJOY_API_KEY environment variable in your environment where this code will be executed. If you're running this in a browser, you'll need to set this in some secure way, as exposing your API key in the client-side JavaScript code is not recommended.